/* Definition for thread-local data handling.  nptl/i386 version.
   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _TLS_H
#define _TLS_H 1

#include <dl-sysdep.h>
#ifndef __ASSEMBLER__
# include <list.h>
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <stdlib.h>


/* Type for the dtv.  */
typedef union dtv {
  size_t counter;
  struct {
    void *val;
    bool is_static;
  } pointer;
} dtv_t;


typedef struct {
  void *tcb;            /* Pointer to the TCB.  Not necessarily the
                           thread descriptor used by libpthread.  */
  dtv_t *dtv;
  void *self;           /* Pointer to the thread descriptor.  */
  int multiple_threads;
  uintptr_t sysinfo;
  uintptr_t stack_guard;
  uintptr_t pointer_guard;
} tcbhead_t;

# define TLS_MULTIPLE_THREADS_IN_TCB 1

#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif // ifndef __ASSEMBLER__


/* We require TLS support in the tools.  */
#ifndef HAVE_TLS_SUPPORT
# error "TLS support is required."
#endif // ifndef HAVE_TLS_SUPPORT

/* Signal that TLS support is available.  */
#define USE_TLS     1

/* Alignment requirement for the stack.  For IA-32 this is governed by
   the SSE memory functions.  */
#define STACK_ALIGN 16

#ifndef __ASSEMBLER__

/* Get system call information.  */
# include <sysdep.h>

/* The old way: using LDT.  */

/* Structure passed to `modify_ldt', 'set_thread_area', and 'clone' calls.  */
struct user_desc {
  unsigned int entry_number;
  unsigned long int base_addr;
  unsigned int limit;
  unsigned int seg_32bit : 1;
  unsigned int contents : 2;
  unsigned int read_exec_only : 1;
  unsigned int limit_in_pages : 1;
  unsigned int seg_not_present : 1;
  unsigned int useable : 1;
  unsigned int empty : 25;
};

/* Initializing bit fields is slow.  We speed it up by using a union.  */
union user_desc_init {
  struct user_desc desc;
  unsigned int vals[4];
};


/* Get the thread descriptor definition.  */
# include <nptl/descr.h>

/* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
   because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
   struct pthread even when not linked with -lpthread.  */
# define TLS_INIT_TCB_SIZE  sizeof(struct pthread)

/* Alignment requirements for the initial TCB.  */
# define TLS_INIT_TCB_ALIGN __alignof__(struct pthread)

/* This is the size of the TCB.  */
# define TLS_TCB_SIZE       sizeof(struct pthread)

/* Alignment requirements for the TCB.  */
# define TLS_TCB_ALIGN      __alignof__(struct pthread)

/* The TCB can have any size and the memory following the address the
   thread pointer points to is unspecified.  Allocate the TCB there.  */
# define TLS_TCB_AT_TP      1


/* Install the dtv pointer.  The pointer passed is to the element with
   index -1 which contain the length.  */
# define INSTALL_DTV(descr, dtvp) \
  ((tcbhead_t *)(descr))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */
# define INSTALL_NEW_DTV(dtvp) \
  ({ struct pthread *__pd;     \
     THREAD_SETMEM(__pd, header.dtv, (dtvp)); })

/* Return dtv of given thread descriptor.  */
# define GET_DTV(descr) \
  (((tcbhead_t *)(descr))->dtv)

# define THREAD_SELF_SYSINFO THREAD_GETMEM(THREAD_SELF, header.sysinfo)
# define THREAD_SYSINFO(pd) ((pd)->header.sysinfo)

/* Macros to load from and store into segment registers.  */
# ifndef TLS_GET_GS
#  define TLS_GET_GS() \
  ({ int __seg; __asm("movw %%gs, %w0" : "=q" (__seg)); __seg& 0xffff; })
# endif // ifndef TLS_GET_GS
# ifndef TLS_SET_GS
#  define TLS_SET_GS(val) \
  __asm("movw %w0, %%gs" ::"q" (val))
# endif // ifndef TLS_SET_GS


# ifndef __NR_set_thread_area
#  define __NR_set_thread_area 243
# endif // ifndef __NR_set_thread_area
# ifndef TLS_FLAG_WRITABLE
#  define TLS_FLAG_WRITABLE    0x00000001
# endif // ifndef TLS_FLAG_WRITABLE

// XXX Enable for the real world.
# if 0
#  ifndef __ASSUME_SET_THREAD_AREA
#   error "we need set_thread_area"
#  endif // ifndef __ASSUME_SET_THREAD_AREA
# endif // if 0

# ifdef __PIC__
#  define TLS_EBX_ARG  "r"
#  define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t"
# else // ifdef __PIC__
#  define TLS_EBX_ARG  "b"
#  define TLS_LOAD_EBX
# endif // ifdef __PIC__

# if defined NEED_DL_SYSINFO
#  define INIT_SYSINFO \
  _head->sysinfo = GLRO(dl_sysinfo)
# else // if defined NEED_DL_SYSINFO
#  define INIT_SYSINFO
# endif // if defined NEED_DL_SYSINFO

# ifndef LOCK_PREFIX
#  ifdef UP
#   define LOCK_PREFIX /* nothing */
#  else // ifdef UP
#   define LOCK_PREFIX "lock;"
#  endif // ifdef UP
# endif // ifndef LOCK_PREFIX

/* Code to initially initialize the thread pointer.  This might need
   special attention since 'errno' is not yet available and if the
   operation can cause a failure 'errno' must not be touched.  */
# define TLS_INIT_TP(thrdescr, secondcall)                          \
  ({ void *_thrdescr = (thrdescr);                                  \
     tcbhead_t *_head = _thrdescr;                                  \
     union user_desc_init _segdescr;                                \
     int _result;                                                   \
                                                                    \
     _head->tcb = _thrdescr;                                        \
     /* For now the thread descriptor is at the same address.  */   \
     _head->self = _thrdescr;                                       \
     /* New syscall handling support.  */                           \
     INIT_SYSINFO;                                                  \
                                                                    \
     /* The 'entry_number' field.  Let the kernel pick a value.  */ \
     if (secondcall) {                                              \
       _segdescr.vals[0] = TLS_GET_GS() >> 3;                       \
     } else {                                                       \
       _segdescr.vals[0] = -1;                                      \
     }                                                              \
     /* The 'base_addr' field.  Pointer to the TCB.  */             \
     _segdescr.vals[1] = (unsigned long int)_thrdescr;              \
     /* The 'limit' field.  We use 4GB which is 0xfffff pages.  */  \
     _segdescr.vals[2] = 0xfffff;                                   \
     /* Collapsed value of the bitfield:				      \
          .seg_32bit = 1						      \
          .contents = 0							      \
          .read_exec_only = 0						      \
          .limit_in_pages = 1						      \
          .seg_not_present = 0						      \
          .useable = 1 */                                               \
     _segdescr.vals[3] = 0x51;                                          \
                                                                        \
     /* Install the TLS.  */                                            \
     asm volatile (TLS_LOAD_EBX                                         \
                   "int $0x80\n\t"                                      \
                   TLS_LOAD_EBX                                         \
                   : "=a" (_result), "=m" (_segdescr.desc.entry_number) \
                   : "0" (__NR_set_thread_area),                        \
                   TLS_EBX_ARG(&_segdescr.desc), "m" (_segdescr.desc)); \
                                                                        \
     if (_result == 0) {                                                \
       /* We know the index in the GDT, now load the segment register.	      \
          The use of the GDT is described by the value 3 in the lower	      \
          three bits of the segment descriptor value.			      \
                                                                              \
          Note that we have to do this even if the numeric value of	      \
          the descriptor does not change.  Loading the segment register	      \
          causes the segment information from the GDT to be loaded	      \
          which is necessary since we have changed it.   */ \
       TLS_SET_GS(_segdescr.desc.entry_number * 8 + 3);     \
     }                                                      \
                                                            \
     _result == 0 ? NULL                                    \
     : "set_thread_area failed when setting up thread-local storage\n"; })


/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV()      \
  ({ struct pthread *__pd; \
     THREAD_GETMEM(__pd, header.dtv); })


/* Return the thread descriptor for the current thread.

   The contained asm must *not* be marked volatile since otherwise
   assignments like
        pthread_descr self = thread_self();
   do not get optimized away.  */
# define THREAD_SELF                                      \
  ({ struct pthread *__self;                              \
     asm ("movl %%gs:%c1,%0" : "=r" (__self)              \
          : "i" (offsetof(struct pthread, header.self))); \
     __self; })

/* Magic for libthread_db to know how to do THREAD_SELF.  */
# define DB_THREAD_SELF                                               \
  REGISTER_THREAD_AREA(32, offsetof(struct user_regs_struct, xgs), 3) \
  REGISTER_THREAD_AREA(64, 26 * 8, 3)  /* x86-64's user_regs_struct->gs */


/* Read member of the thread descriptor directly.  */
# define THREAD_GETMEM(descr, member)                                    \
  ({ __typeof(descr->member) __value;                                    \
     if (sizeof(__value) == 1) {                                         \
       asm volatile ("movb %%gs:%P2,%b0"                                 \
                     : "=q" (__value)                                    \
                     : "0" (0), "i" (offsetof(struct pthread, member))); \
     } else if (sizeof(__value) == 4) {                                  \
       asm volatile ("movl %%gs:%P1,%0"                                  \
                     : "=r" (__value)                                    \
                     : "i" (offsetof(struct pthread, member)));          \
     } else {                                                            \
       if (sizeof(__value) != 8) {                                       \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                           \
         abort();                                                 \
       }                                                          \
                                                                  \
       asm volatile ("movl %%gs:%P1,%%eax\n\t"                    \
                     "movl %%gs:%P2,%%edx"                        \
                     : "=A" (__value)                             \
                     : "i" (offsetof(struct pthread, member)),    \
                     "i" (offsetof(struct pthread, member) + 4)); \
     }                                                            \
     __value; })


/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
# define THREAD_GETMEM_NC(descr, member, idx)                              \
  ({ __typeof(descr->member[0]) __value;                                   \
     if (sizeof(__value) == 1) {                                           \
       asm volatile ("movb %%gs:%P2(%3),%b0"                               \
                     : "=q" (__value)                                      \
                     : "0" (0), "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                           \
     } else if (sizeof(__value) == 4) {                                    \
       asm volatile ("movl %%gs:%P1(,%2,4),%0"                             \
                     : "=r" (__value)                                      \
                     : "i" (offsetof(struct pthread, member[0])),          \
                     "r" (idx));                                           \
     } else {                                                              \
       if (sizeof(__value) != 8) {                                         \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                           \
         abort();                                                 \
       }                                                          \
                                                                  \
       asm volatile ("movl %%gs:%P1(,%2,8),%%eax\n\t"             \
                     "movl %%gs:4+%P1(,%2,8),%%edx"               \
                     : "=&A" (__value)                            \
                     : "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                  \
     }                                                            \
     __value; })


/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
# define THREAD_SETMEM(descr, member, value)                  \
  ({ if (sizeof(descr->member) == 1) {                        \
       asm volatile ("movb %b0,%%gs:%P1" :                    \
                     : "iq" (value),                          \
                     "i" (offsetof(struct pthread, member))); \
     } else if (sizeof(descr->member) == 4) {                 \
       asm volatile ("movl %0,%%gs:%P1" :                     \
                     : "ir" (value),                          \
                     "i" (offsetof(struct pthread, member))); \
     } else {                                                 \
       if (sizeof(descr->member) != 8) {                      \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                           \
         abort();                                                 \
       }                                                          \
                                                                  \
       asm volatile ("movl %%eax,%%gs:%P1\n\t"                    \
                     "movl %%edx,%%gs:%P2" :                      \
                     : "A" (value),                               \
                     "i" (offsetof(struct pthread, member)),      \
                     "i" (offsetof(struct pthread, member) + 4)); \
     } })


/* Set member of the thread descriptor directly.  */
# define THREAD_SETMEM_NC(descr, member, idx, value)         \
  ({ if (sizeof(descr->member[0]) == 1) {                    \
       asm volatile ("movb %b0,%%gs:%P1(%2)" :               \
                     : "iq" (value),                         \
                     "i" (offsetof(struct pthread, member)), \
                     "r" (idx));                             \
     } else if (sizeof(descr->member[0]) == 4) {             \
       asm volatile ("movl %0,%%gs:%P1(,%2,4)" :             \
                     : "ir" (value),                         \
                     "i" (offsetof(struct pthread, member)), \
                     "r" (idx));                             \
     } else {                                                \
       if (sizeof(descr->member[0]) != 8) {                  \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                      \
         abort();                                            \
       }                                                     \
                                                             \
       asm volatile ("movl %%eax,%%gs:%P1(,%2,8)\n\t"        \
                     "movl %%edx,%%gs:4+%P1(,%2,8)" :        \
                     : "A" (value),                          \
                     "i" (offsetof(struct pthread, member)), \
                     "r" (idx));                             \
     } })


/* Atomic compare and exchange on TLS, returning old value.  */
# define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
  ({ __typeof(descr->member) __ret;                               \
     __typeof(oldval) __old = (oldval);                           \
     if (sizeof(descr->member) == 4) {                            \
       asm volatile (LOCK_PREFIX "cmpxchgl %2, %%gs:%P3"          \
                     : "=a" (__ret)                               \
                     : "0" (__old), "r" (newval),                 \
                     "i" (offsetof(struct pthread, member)));     \
     } else {                                                     \
       /* Not necessary for other sizes in the moment.  */        \
       abort();                                                   \
     }                                                            \
     __ret; })


/* Atomic set bit.  */
# define THREAD_ATOMIC_BIT_SET(descr, member, bit)                   \
  (void)({ if (sizeof((descr)->member) == 4) {                       \
             asm volatile (LOCK_PREFIX "orl %1, %%gs:%P0"            \
                           ::"i" (offsetof(struct pthread, member)), \
                           "ir" (1 << (bit)));                       \
           } else {                                                  \
             /* Not necessary for other sizes in the moment.  */     \
             abort();                                                \
           } })


/* Call the user-provided thread function.  */
# define CALL_THREAD_FCT(descr)                                       \
  ({ void *__res;                                                     \
     int __ignore1, __ignore2;                                        \
     asm volatile ("pushl %%eax\n\t"                                  \
                   "pushl %%eax\n\t"                                  \
                   "pushl %%eax\n\t"                                  \
                   "pushl %%gs:%P4\n\t"                               \
                   "call *%%gs:%P3\n\t"                               \
                   "addl $16, %%esp"                                  \
                   : "=a" (__res), "=c" (__ignore1), "=d" (__ignore2) \
                   : "i" (offsetof(struct pthread, start_routine)),   \
                   "i" (offsetof(struct pthread, arg)));              \
     __res; })


/* Set the stack guard field in TCB head.  */
# define THREAD_SET_STACK_GUARD(value) \
  THREAD_SETMEM(THREAD_SELF, header.stack_guard, value)
# define THREAD_COPY_STACK_GUARD(descr) \
  ((descr)->header.stack_guard          \
     = THREAD_GETMEM(THREAD_SELF, header.stack_guard))


/* Set the pointer guard field in the TCB head.  */
# define THREAD_SET_POINTER_GUARD(value) \
  THREAD_SETMEM(THREAD_SELF, header.pointer_guard, value)
# define THREAD_COPY_POINTER_GUARD(descr) \
  ((descr)->header.pointer_guard          \
     = THREAD_GETMEM(THREAD_SELF, header.pointer_guard))
#endif /* __ASSEMBLER__ */
#endif  /* tls.h */
